This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Inhibition of Rho kinase (ROCK) activity by fasudil ameliorates progression of diabetic nephropathy (DN). However, fasudil is not selective, and can not distinguish the pathogenic roles of ROCK-1 vs. ROCK-2, two different isomers of ROCK, in DN. Therefore in the current study, we will use a genetic approach. We generated ROCK1-/- mice on FVB background. These mice are phenotypically normal. Specific Aim: To evaluate the role of ROCK1 on mitochondrial fragmentation. We observed that ROCK1-/- diabetic mice demonstrated a significant reduction in mitochondrial fragmentation compared to wild type diabetic mice. Therefore, we are planning to evaluate the role of ROCK1 on mitochondrial fragmentation in glomerular podocytes with 2D and 3D EM. To this end, none diabetic and diabetic mice will be perfused, and their kidneys fixed and prepared for stained, plastic embedding and sectioning. Based on a previous study, we plan to reconstruct mitochondrial structure from serial sections of a representative region to confirm the mitochondrial fragmentation in podocytes from diabetic mice.